[SyntaxParse] Refactor parsing facilities

include/swift/Parse/ASTGen.h

@@ -97,10 +97,6 @@ class ASTGen {
 
   static SourceLoc advanceLocBegin(const SourceLoc &Loc,
                                    const syntax::Syntax &Node);
-  static SourceLoc advanceLocEnd(const SourceLoc &Loc,
-                                 const syntax::TokenSyntax &Token);
-  static SourceLoc advanceLocAfter(const SourceLoc &Loc,
-                                   const syntax::Syntax &Node);
 
   static MagicIdentifierLiteralExpr::Kind getMagicIdentifierLiteralKind(tok Kind);
 

include/swift/Parse/Parser.h

@@ -695,6 +695,25 @@ class Parser {
   /// plain Tok.is(T1) check).
   bool skipUntilTokenOrEndOfLine(tok T1);
 
+  void ignoreToken();
+  void ignoreToken(tok Kind) {
+    assert(Tok.is(Kind));
+    ignoreToken();
+  }
+  bool ignoreIf(tok Kind) {
+    if (!Tok.is(Kind))
+      return false;
+    ignoreToken();
+    return true;
+  }
+  void ignoreSingle();
+  void ignoreUntil(tok Kind);
+
+  /// Ignore tokens until a token that starts with '>', and return true it if
+  /// found. Applies heuristics that are suitable when trying to find the end
+  /// of a list of generic parameters, generic arguments.
+  bool ignoreUntilGreaterInTypeList();
+
   /// If the parser is generating only a syntax tree, try loading the current
   /// node from a previously generated syntax tree.
   /// Returns \c true if the node has been loaded and inserted into the current
@@ -1153,10 +1172,13 @@ class Parser {
 
   using TypeASTResult = ParserResult<TypeRepr>;
   using TypeResult = ParsedSyntaxResult<ParsedTypeSyntax>;
-  using TypeErrorResult = ParsedSyntaxResult<ParsedUnknownTypeSyntax>;
 
   LayoutConstraint parseLayoutConstraint(Identifier LayoutConstraintID);
 
+  TypeResult parseTypeSyntax();
+  TypeResult parseTypeSyntax(Diag<> MessageID, bool HandleCodeCompletion = true,
+                             bool IsSILFuncDecl = false);
+
   TypeASTResult parseType();
   TypeASTResult parseType(Diag<> MessageID, bool HandleCodeCompletion = true,
                           bool IsSILFuncDecl = false);
@@ -1183,8 +1205,8 @@ class Parser {
   TypeResult parseOptionalType(ParsedTypeSyntax Base);
   TypeResult parseImplicitlyUnwrappedOptionalType(ParsedTypeSyntax Base);
 
-  TypeErrorResult parseTypeArray(ParsedTypeSyntax Base, SourceLoc BaseLoc);
-  TypeErrorResult parseOldStyleProtocolComposition();
+  TypeResult parseTypeArray(ParsedTypeSyntax Base, SourceLoc BaseLoc);
+  TypeResult parseOldStyleProtocolComposition();
 
   bool isOptionalToken(const Token &T) const;
   ParsedTokenSyntax consumeOptionalTokenSyntax();

include/swift/Parse/SyntaxParserResult.h

@@ -30,215 +30,103 @@ template <typename ParsedSyntaxNode> class ParsedSyntaxResult {
   friend class ParsedSyntaxResult;
 
 private:
-  // todo [gsoc]: use some kind of a proper sum type
-  llvm::Optional<ParsedSyntaxNode> SuccessNode;
-  llvm::Optional<llvm::SmallVector<ParsedSyntax, 0>> ErrorNodes;
-  llvm::Optional<llvm::SmallVector<ParsedSyntax, 0>> CodeCompletionNodes;
-
-  ResultDataKind DK;
+  ParsedRawSyntaxNode Raw;
+  ParserStatus Status;
 
 public:
-  explicit ParsedSyntaxResult(ParsedSyntaxNode Node)
-      : SuccessNode(Node), DK(ResultDataKind::Success) {}
-
-  ParsedSyntaxResult(ArrayRef<ParsedSyntax> Nodes,
-                     ResultDataKind Kind)
-      : DK(Kind) {
-    switch (DK) {
-    case ResultDataKind::Error:
-      ErrorNodes.emplace(Nodes.begin(), Nodes.end());
-      break;
-    case ResultDataKind::CodeCompletion:
-      CodeCompletionNodes.emplace(Nodes.begin(), Nodes.end());
-      break;
-    default:
-      llvm_unreachable("success cannot contain multiple nodes");
-    }
-  }
+  explicit ParsedSyntaxResult() : Raw(), Status() { setIsError(); }
 
-  ParsedSyntaxResult(const ParsedSyntaxResult &Other) {
-    DK = Other.DK;
-
-    switch (DK) {
-    case ResultDataKind::Success:
-      SuccessNode = Other.SuccessNode;
-      break;
-    case ResultDataKind::Error:
-      ErrorNodes = Other.ErrorNodes;
-      break;
-    case ResultDataKind::CodeCompletion:
-      CodeCompletionNodes = Other.CodeCompletionNodes;
-      break;
-    }
+  ParsedSyntaxResult(ParserStatus Status) : Raw(), Status(Status) {
+    assert(Status.isError());
   }
 
+  explicit ParsedSyntaxResult(ParsedRawSyntaxNode Raw)
+      : Raw(Raw), Status() {}
+
+  explicit ParsedSyntaxResult(ParsedSyntaxNode Node)
+      : ParsedSyntaxResult(Node.getRaw()) {}
+
   template <typename OtherParsedSyntaxNode,
             typename Enable = typename std::enable_if<std::is_base_of<
                 ParsedSyntaxNode, OtherParsedSyntaxNode>::value>::type>
-  ParsedSyntaxResult(ParsedSyntaxResult<OtherParsedSyntaxNode> Other) {
-    DK = Other.DK;
-
-    switch (DK) {
-    case ResultDataKind::Success:
-      SuccessNode = *Other.SuccessNode;
-      break;
-    case ResultDataKind::Error:
-      ErrorNodes = *Other.ErrorNodes;
-      break;
-    case ResultDataKind::CodeCompletion:
-      CodeCompletionNodes = *Other.CodeCompletionNodes;
-      break;
-    }
+  ParsedSyntaxResult(ParsedSyntaxResult<OtherParsedSyntaxNode> other) {
+    Raw = other.Raw;
+    Status = other.Status;
   }
 
   bool isSuccess() const {
-    return DK == ResultDataKind::Success;
+    return Status.isSuccess();
   }
 
   bool isError() const {
-    return DK == ResultDataKind::Error;
+    return Status.isError();
+  }
+  void setIsError() {
+    Status.setIsParseError();
   }
 
-  bool isCodeCompletion() const {
-    return DK == ResultDataKind::CodeCompletion;
+  bool hasCodeCompletion() const {
+    return Status.hasCodeCompletion();
+  }
+  void setHasCodeCompletion() {
+    Status.setHasCodeCompletion();
   }
 
-  ParsedSyntaxNode getResult() const {
-    assert(isSuccess() && "unsuccessful parse doesn't have any result");
-    return *SuccessNode;
+  ParsedSyntaxNode get() const {
+    assert(!isNull());
+    return ParsedSyntaxNode(Raw);
+  }
+  Optional<ParsedSyntaxNode> getOrNull() const {
+    if (isNull())
+      return None;
+    return get();
   }
 
-  ArrayRef<ParsedSyntax> getUnknownNodes() const {
-    assert(!isSuccess() && "successful parse doesn't contain unknown nodes");
-    switch (DK) {
-    case ResultDataKind::Error:
-      return *ErrorNodes;
-    case ResultDataKind::CodeCompletion:
-      return *CodeCompletionNodes;
-    default:
-      llvm_unreachable("cannot get here");
-    }
+  bool isNull() const {
+    return Raw.isNull();
   }
-  
+
   ParserStatus getStatus() const {
-    ParserStatus S;
-    if (isError())
-      S.setIsParseError();
-    if (isCodeCompletion())
-      S.setHasCodeCompletion();
-    return S;
+    return Status;
   }
 };
 
 template <typename ParsedSyntaxNode>
 static ParsedSyntaxResult<ParsedSyntaxNode>
-makeParsedSuccess(ParsedSyntaxNode Node) {
-  return ParsedSyntaxResult<ParsedSyntaxNode>(Node);
+makeParsedResult(ParsedSyntaxNode node) {
+  return ParsedSyntaxResult<ParsedSyntaxNode>(node);
 }
 
 template <typename ParsedSyntaxNode>
 static ParsedSyntaxResult<ParsedSyntaxNode>
-makeParsedError(ArrayRef<ParsedSyntax> Nodes) {
-  return ParsedSyntaxResult<ParsedSyntaxNode>(Nodes, ResultDataKind::Error);
+makeParsedError(ParsedSyntaxNode node) {
+  auto result = ParsedSyntaxResult<ParsedSyntaxNode>(node);
+  result.setIsError();
+  return result;
 }
 
 template <typename ParsedSyntaxNode>
-static ParsedSyntaxResult<ParsedSyntaxNode> makeParsedErrorEmpty() {
-  return ParsedSyntaxResult<ParsedSyntaxNode>({}, ResultDataKind::Error);
+static ParsedSyntaxResult<ParsedSyntaxNode> makeParsedError() {
+  return ParsedSyntaxResult<ParsedSyntaxNode>();
 }
 
 template <typename ParsedSyntaxNode>
 static ParsedSyntaxResult<ParsedSyntaxNode>
-makeParsedCodeCompletion(ArrayRef<ParsedSyntax> Nodes) {
-  return ParsedSyntaxResult<ParsedSyntaxNode>(Nodes,
-                                              ResultDataKind::CodeCompletion);
+makeParsedCodeCompletion(ParsedSyntaxNode node) {
+  auto result = ParsedSyntaxResult<ParsedSyntaxNode>(node);
+  result.setHasCodeCompletion();
+  return result;
 }
 
 template <typename ParsedSyntaxNode>
 static ParsedSyntaxResult<ParsedSyntaxNode>
-makeParsedResult(ArrayRef<ParsedSyntax> Nodes,
-                 ParserStatus Status) {
-  return Status.hasCodeCompletion()
-             ? makeParsedCodeCompletion<ParsedSyntaxNode>(Nodes)
-             : makeParsedError<ParsedSyntaxNode>(Nodes);
-}
-
-template <typename Syntax, typename AST> class SyntaxParserResult {
-  llvm::Optional<Syntax> SyntaxNode;
-  ParserResult<AST> ASTResult;
-
-  template <typename T, typename U> friend class SyntaxParserResult;
-
-public:
-  SyntaxParserResult(std::nullptr_t = nullptr)
-      : SyntaxNode(None), ASTResult(nullptr) {}
-  SyntaxParserResult(ParserStatus Status)
-      : SyntaxNode(None), ASTResult(Status) {}
-  SyntaxParserResult(llvm::Optional<Syntax> SyntaxNode, AST *ASTNode)
-      : SyntaxNode(SyntaxNode), ASTResult(ASTNode) {}
-  SyntaxParserResult(ParserStatus Status, llvm::Optional<Syntax> SyntaxNode,
-                     AST *ASTNode)
-      : SyntaxNode(SyntaxNode), ASTResult(makeParserResult(Status, ASTNode)) {}
-
-  /// Convert from a different but compatible parser result.
-  template <typename U, typename Enabler = typename std::enable_if<
-                            std::is_base_of<AST, U>::value>::type>
-  SyntaxParserResult(SyntaxParserResult<Syntax, U> Other)
-      : SyntaxNode(Other.SyntaxNode), ASTResult(Other.ASTResult) {}
-
-
-  bool isNull() const { return ASTResult.isNull(); }
-  bool isNonNull() const { return ASTResult.isNonNull(); }
-  bool isParseError() const { return ASTResult.isParseError(); }
-  bool hasCodeCompletion() const { return ASTResult.hasCodeCompletion(); }
-
-  void setIsParseError() { return ASTResult.setIsParserError(); }
-  void setHasCodeCompletion() { return ASTResult.setHasCodeCompletion(); }
-
-  const ParserResult<AST> &getASTResult() { return ASTResult; }
-
-  AST *getAST() const { return ASTResult.get(); }
-
-  bool hasSyntax() const {
-    return SyntaxNode.hasValue();
-  }
-
-  Syntax getSyntax() const {
-    assert(SyntaxNode.hasValue() && "getSyntax from None value");
-    return *SyntaxNode;
-  }
-
-  SyntaxParserResult<Syntax, AST> &
-  operator=(SyntaxParserResult<Syntax, AST> R){
-    std::swap(*this, R);
-    return *this;
-  };
-};
-
-/// Create a successful parser result.
-template <typename Syntax, typename AST>
-static inline SyntaxParserResult<Syntax, AST>
-makeSyntaxResult(llvm::Optional<Syntax> SyntaxNode, AST *ASTNode) {
-  return SyntaxParserResult<Syntax, AST>(SyntaxNode, ASTNode);
-}
-
-/// Create a result with the specified status.
-template <typename Syntax, typename AST>
-static inline SyntaxParserResult<Syntax, AST>
-makeSyntaxResult(ParserStatus Status, llvm::Optional<Syntax> SyntaxNode,
-                 AST *ASTNode) {
-  return SyntaxParserResult<Syntax, AST>(Status, SyntaxNode, ASTNode);
-}
-
-/// Create a result (null or non-null) with error and code completion bits set.
-template <typename Syntax, typename AST>
-static inline SyntaxParserResult<Syntax, AST>
-makeSyntaxCodeCompletionResult(AST *Result = nullptr) {
-  SyntaxParserResult<Syntax, AST> SR;
-  if (Result)
-    SR = SyntaxParserResult<Syntax, AST>(None, Result);
-  SR.setHasCodeCompletion();
-  return SR;
+makeParsedResult(ParsedSyntaxNode node, ParserStatus Status) {
+  auto result = ParsedSyntaxResult<ParsedSyntaxNode>(node);
+  if (Status.hasCodeCompletion())
+    result.setHasCodeCompletion();
+  else if (Status.isError())
+    result.setIsError();
+  return result;
 }
 
 } // namespace swift